MAC address synchronization in a fabric switch

• US 9,774,543 B2
• Filed: 08/03/2016
• Issued: 09/26/2017
• Est. Priority Date: 01/11/2013
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Brocade Communications Systems, Inc. (Broadcom, Inc.)
• Inventors: Venkatesh, Vardarajan
• Primary Examiner(s): HAILE, AWET A
• Application Number:
  US15/227,789
• Publication Number:
  US 20160344658A1
• Time in Patent Office: 419 Days
• CPC Class Codes: H04L 49/10 characterised by the switching fabric construction
• CPC Class Codes: H04L 49/111 Switch interfaces, e.g. port details
• CPC Class Codes: H04L 49/118 Address processing within a device, e.g. using internal ID or tags for routing within a switch
• CPC Class Codes: H04L 7/0037 Delay of clock signal
• CPC Class Codes: H04L 7/0041 Delay of data signal
• CPC Class Codes: H04L 7/0337 Selecting between two or more discretely delayed clocks or selecting between two or more discretely delayed received code signals

Abstract

One embodiment of the present invention provides a system for facilitating synchronization of MAC addresses in a fabric switch. During operation, the system divides a number of media access control (MAC) addresses associated with devices coupled to an interface of the switch. The system then computes a checksum for a respective chunk of MAC addresses. In addition, the system broadcasts MAC address information of the chunk to facilitate MAC address synchronization in a fabric switch of which the switch is a member, and to manage the chunks and their corresponding checksum, thereby correcting an unsynchronized or race condition in the fabric switch.

Claims

1. A switch, comprising:

chunking circuitry configured to maintain a local copy of a chunk comprising a plurality of media access control (MAC) addresses, wherein a respective MAC address in the local copy of the chunk is associated with an indicator indicating that the MAC address is learned at a remote switch, and wherein the switch and the remote switch are members of a network of interconnected switches;

MAC synchronization circuitry configured to;

obtain, from a message from the remote switch, a copy of the chunk and validation information associated with the chunk; and

determine whether to update the local copy of the chunk based on the validation information from the message.

2. The switch of claim 1, wherein the plurality of media access control (MAC) addresses are associated with devices coupled to a virtual link aggregation group (VLAG), wherein the VLAG includes a plurality of links operating as a single logical link.

3. The switch of claim 1, wherein the MAC synchronization circuitry is further configured to store a checksum with the local copy of the chunk.

4. The switch of claim 3, wherein the MAC synchronization circuitry determines whether to update the local copy of the chunk by:

obtaining a checksum from the validation information; and

determining whether the obtained checksum is different than the stored checksum.

5. The switch of claim 4, wherein the MAC synchronization circuitry is further configured to:

in response to determining that the obtained checksum is different than the stored checksum, construct a response message for the remote switch, wherein the response message indicates the difference;

determine, based on a confirmation message from the remote switch, that the difference is not a race condition; and

update the local copy of the chunk with the obtained copy of the chunk.

6. The switch of claim 1, wherein updating the local copy of the chunk includes one or more of:

adding entries associated with a difference between the local copy of the chunk and the obtained copy of the chunk;

deleting entries associated with the difference between the local copy of the chunk and the obtained copy of the chunk; and

performing no operation for entries common to the local copy of the chunk and the obtained copy of the chunk.

7. The switch of claim 1, wherein the message further comprises a chunk identifier, which identifies the chunk.

8. A method, comprising:

maintaining, by a switch, a local copy of a chunk comprising a plurality of media access control (MAC) addresses, wherein a respective MAC address of the chunk is associated with an indicator indicating that the MAC address is learned at a remote switch, and wherein the switch and the remote switch are members of a network of interconnected switches;

obtaining, from a message from the remote switch, a copy of the chunk and validation information associated with the chunk; and

determining whether to update the local copy of the chunk based on the validation information from the message.

9. The method of claim 8, wherein the plurality of media access control (MAC) addresses are associated with devices coupled to a virtual link aggregation group (VLAG), wherein the VLAG includes a plurality of links operating as a single logical link.

10. The method of claim 8, further comprising storing a checksum with the local copy of the chunk.

11. The method of claim 10, wherein determining whether to update the local copy of the chunk comprises:

obtaining a checksum from the validation information; and

determining whether the obtained checksum is different than the stored checksum.

12. The method of claim 11, further comprising:

in response to determining that the obtained checksum is different than the stored checksum, construct a response message for the remote switch, wherein the response message indicates the difference;

determine, based on a confirmation message from the remote switch, that the difference is not a race condition; and

update the local copy of the chunk with the obtained copy of the chunk.

13. The method of claim 10, wherein updating the local copy of the chunk includes one or more of:

adding entries associated with a difference between the local copy of the chunk and the obtained copy of the chunk;

deleting entries associated with the difference between the local copy of the chunk and the obtained copy of the chunk; and

performing no operation for entries common to the local copy of the chunk and the obtained copy of the chunk.

14. The method of claim 8, wherein the message further comprises a chunk identifier, which identifies the chunk.

15. A computing system, comprising:

a processor; and

a storage device storing instructions which when executed by the processor cause the processor to perform a method, the method comprising;

maintaining, by a switch, a local copy of a chunk comprising a plurality of media access control (MAC) addresses, wherein a respective MAC address of in the local copy the chunk is associated with an indicator indicating that the MAC address is learned at a remote switch, and wherein the switch and the remote switch are members of a network of interconnected switches;

obtaining, from a message from the remote switch, a copy of the chunk and validation information associated with the chunk; and

determining whether to update the local copy of the chunk based on the validation information from the message.

16. The computing system of claim 15, wherein the method further comprises storing a checksum with the local copy of the chunk.

17. The computing system of claim 16, wherein determining whether to update the local copy of the chunk comprises:

obtaining a checksum from the validation information; and

determining whether the obtained checksum is different than the stored checksum.

18. The computing system of claim 17, wherein the method further comprises:

in response to determining that the obtained checksum is different than the stored checksum, construct a response message for the remote switch, wherein the response message indicates the difference;

determine, based on a confirmation message from the remote switch, that the difference is not a race condition; and

update the local copy of the chunk with the obtained copy of the chunk.

19. The computing system of claim 15, wherein updating the local copy of the chunk includes one or more of:

adding entries associated with a difference between the local copy of the chunk and the obtained copy of the chunk;

deleting entries associated with the difference between the local copy of the chunk and the obtained copy of the chunk; and

performing no operation for entries common to the local copy of the chunk and the obtained copy of the chunk.

20. The computing system of claim 15, wherein the message further comprises a chunk identifier, which identifies the chunk.